Added haskell-dev environment

hosts/teintidh.nix

@@ -7,6 +7,7 @@
     [
       ../hardware/lenovo_x201.nix
       ../roles/desktop_common.nix
+      ../roles/haskell-dev.nix
     ];
 
   # Use the GRUB 2 boot loader.

roles/haskell-dev.nix

@@ -0,0 +1,11 @@
+# Configuration for Haskell development
+
+{ config, pkgs, ... }:
+
+{
+
+  environment.systemPackages = with pkgs; [
+    haskellPackages.ghc   # Glasgow Haskell Compiler
+  ];
+
+}

roles/nCovid-19.nix

@@ -0,0 +1,14 @@
+# NixOps configuration for the hosts utilising Folding@Home for nCovid-19
+
+{ config, pkgs, lib, ... }:
+
+{
+
+  # Set the system-wide environment
+  environment = {
+    systemPackages = with pkgs; [
+      foldingathome    # Folding@home distributed computing client
+    ];
+  };
+
+}